Going Nuclear: Positron Emission Tomography in Acute Pericarditis
A 26-year-old woman with a history of secundum atrial septal defect and patent ductus arteriosus (PDA) for which she underwent surgical closure 23 years prior to presentation followed by coil closure of a recanalized PDA 10 years later with a stainless steel coil was seen in clinic for recurrent pleuritic chest pain.
She describes five prior episodes of pleuritic chest pain radiating to her right shoulder over the past 4 years. During her fourth episode she was evaluated by a local cardiologist and was found on exam to have a pericardial friction rub, PR depressions on electrocardiogram (ECG) and a small pericardial effusion on echocardiogram. With all four diagnostic criteria met, she was diagnosed with acute pericarditis and started on colchicine and ibuprofen. She reports taking ibuprofen for approximately one week until her symptoms resolved and was gradually tapered off colchicine over three months. Her fifth and most recent episode of pleuritic chest pain occurred two months prior to presentation. She was again seen by her local cardiologist and lab work was notable for elevated erythrocyte sediment rate (ESR) and C-reactive protein (CRP). She was restarted on colchicine and non-steroidal anti-inflammatory medications. Her symptoms resolved within two weeks and she self-discontinued both medications.
On current presentation she endorsed severe pleuritic chest pain radiating to her upper back that started several days prior. On exam she was febrile to 102.7 degrees Fahrenheit, her blood pressure was 129/60 mmHg and she was tachycardic to 116 beats per minute. Her cardiac exam was remarkable for a pericardial friction rub. Her labs were notable for a white blood cell count of 17 (normal range 3.7-11.0 k/uL), ESR of 71 mm/hr (normal <20 mm/hr) and CRP of 33.5 (normal <0.9 mg/dL). Her ECG (Figure 1) demonstrated subtle diffuse J point elevation and sub-millimeter PR depressions most pronounced in the inferior leads. Echocardiogram (Figure 2) demonstrated a small circumferential pericardial effusion (0.8 cm), a normal appearing inferior vena cava measuring 1.6 cm with greater than 50 percent collapsibility with inspiration, right atrial tethering with respirophasic shift of the intraventricular septum and a diastolic septal bounce suggestive of early effusive-constrictive physiology.
She was admitted for management of acute recurrent pericarditis. Given her history of recurrent pericarditis, additional imaging was pursued to assess the degree of pericardial inflammation. Delayed enhancement imaging after administration of intravenous gadolinium on cardiac magnetic resonance (CMR) is typically the modality of choice to characterize the pericardium. However, given the presence of her prior PDA coil, CMR could not be obtained. She subsequently underwent 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) imaging.
Which of the following findings on 18F-FDG PET imaging is suggestive of acute pericarditis?